Wetting agent and detergent aid



Patented Oct. 22, 1940 2,219,050 WETTING AGENT AND DETERGENT AID LouisA. Mikeska, Roselle, N. J assignor to Standard Oil Development Company,a corporation of Delaware No Drawing.

12 Claims.

This invention relates to improved detergent aids and wetting agents.More particularly, it relates to high wetting power salts of phosphoricacid partially esterifled by hydroxy aromatic compounds containingsuitable hydrocarbon substituent groups.

By wetting agent is meant substances which improve spreading of surfacecoatings, increase spreading and penetrating power of liquids, such asaqueous solutions and oils, and which may act as detergent aids,emulsifying agents, and dispersing agents, all of these actionsdependingsomewhat upon changes of interfacial and surface tension.

The wetting power of these agents can be evaluated by simple and rapidmethods which measure the relative time taken for an aqueous solution ofan agent to thoroughly penetrate, under prescribed conditions, a fabricor skein of flbres having a prescribed composition, form, and size.Although these methods more particularly compare the penetrating anddetergent aiding action of the agents, they indicate, in general, thecapacities of the agents to perform other wetting functions.

Although wetting agents and detergent aids have been prepared byneutralizing acid esters formed by reacting gaseous olefins with phenolin the presence of sulfuric acid, it has been found that salts ofphosphoric acid partially esterifled by phenolic compounds are properlyconstltuted for high wetting power when the phenolic compounds containsuitable hydrocarbon constituents prior to esteriflcation withphosphoric acid or its condensible derivatives. While the salts ofsulfuric acid partially esterifled. by alkylated phenols can be preparedby having the alkylation step occur during the esteriflcation, there areapplications in which such salts are less desirable due to corrosivenesstendencies of their hydrolysis products.

, An object of this invention is'to producefrom phenolic compounds andphosphoric acid or its condensible derivatives, wetting agents anddetergent aids which have high wetting and -deter-- gent effectivenesswith restricted hydrolysis.

Another object of this invention is to prepare acid esters of phosphoricacid which on neutralization produce stable salts having wetting pow- 5ers comparable to the most effective ester salt derivatives of sulfuricacid, and in some applications, even greater wetting powers, yet withoutcorrosive tendencies of the sulfuric acid ester salts.

A further object of this invention is to pro- Application December 31,1938, Serial'No. 248,900

(Cl. 260-461) I vide monoand di-esters of alkyl phenols and phosphoricacid and to provide such esters which can be reacted with alkali metalbases, to form naphtha-insoluble'and ether-insoluble salts having highwetting numbers in aqueous solutions. 5 Other specific objects willappear from the description which follows. I

These objects are achieved by partially esterifylng phosphoric acid, ora halogen derivative thereof, with selected phenolic compounds to ob- 1otain acid esters which are subsequently neutralized to form the desiredsalts. Suitable alkyl phenols to be used as starting materials may, beobtained by alleviation of lower phenols present in coal tar. fractionsor tar acids. Petroleum 1! phenols, per se, are very suitable. But, thephenolic compounds are preferably selected when they have alkyl sidechains, either simple straight chain or cyclic, containing sufficientsaturated carbon atoms to make'a total of about 0 5 to carbon atoms permolecule of acid ester formed in the esterification. As a rule, thewetting power decreases, while the detergent powerincreases, withincrease in the size of the hydrocarbon substituent. For optimumresults, 5 the phenolic compounds having hydrocarbon side groupscontaining about 3 to 10 saturated carbon atoms per molecule, arepreferred for producing'di-ester salts. More exactly, the diester saltshould contain 5 to 20 alkyl or cycloalkyl carbon atoms per molecule,that is, it is formed from the reaction of allgyl phenols having anaverage-of 2.5 to 10 alkyl carbon atoms per molecule. In forming themono-ester, it is best to esterify a phenol having at least 5 carbonatoms in the hydrocarbon side chain.

Synthetic alkyl phenols'may be prepared by any of the known methods ofalkylation. Suitable methods for their preparation are disclosed in U.S. Patent 1,948,287-of'February 20, 1934, o to Hyym E. Buc and RubenSchuler, and U. S. Patent 1,954,985 of April 17, 1934, to Hyym E. Buc.These patents describe methods for alkylating phenolic compounds such asphenol, cresols, etc., with olefinic hydrocarbons having 5 more than 2carbon atoms'per molecule and similar reactants. They indicate reactionsof alkylating compounds with the phenolic compounds in the presence ofstrong sulfuric acid at controlled temperatures. The allnvl substltuentsformed may be normal, iso, secondary, or tertiary.

The phenolic compounds may contain more than one alkyl substituent andother aliphatic or cycloaliphatic hydrocarbon substituents which supplythe proper number of saturated carbon atoms which may be designated asparaflinic carbon atoms. Petroleum phenols which to some extent simulatephenolic compounds containing a polymethylene or cycloalkyl side group,according to their hydrogen and carbon analyses, have been found to beas satisfactory as alkyl phenols of corresponding or even highermolecular weights. Polyalkyl phenols may be obtained by alkylating lowerphenols with suitable alkylating agents such as alcohols, olefins, alkylsulfates, and alkyl halides, and these alkylating agents may be obtainedfrom cracked petroleum hydrocarbon products.

Compounds which are to be preferably produced according to the presentinvention may be represented as including types having the followinggeneralized compositions and structures:

where R represents 1 or several alkyl substituents containing an averagetotal of 5 to 20 saturated carbon atoms, Ar represents an aromaticnucleus, and M stands for a basic metal atom. It is to be noted that thesalts may be formed from a monoor di-ester of phosphoric acid,orthophosphoric acid being the esterifying acid in obtaining either thedior mono-basic salt, metaand pyrophosphoric acids being adapted forforming the di-basic salt, and halogen derivatives of the acid, e. g.,POCla or PCls being used in some reactions to advantage in place oforthophosphoric acid. The desired partial esters containing thetervalent radical, EP=O, are thus obtained by using pentavalentphosphorus compounds which on hydrolysis yield phosphoric acid. Thefollowing equations, wherein R represents a hydrocarbon side group, aretypical of the reactions carried out:

P o a 211.0 l\ O o oa (BOO) P0Ol+2NaOH (BOO) POONa+Na0l i To prepare asodium salt of di(tertiary amylphenyl) phosphate, 9. one liter three-wayflask Tertiary amyl phe n'm 164 D=\P gms 85 Tnluene N 250 The abovematerials werestirred and heated to 118 C. for 20 hours. Hydrogenchloride gas was liberated copiously in the early part of the reactionand at the end of this time the evolution of hydrogen chloride gas wasslight. The toluene and excess POCla was distilled off and the residuewas added slowly to stirred cracked ice. The aqueous solution wasextracted with ether and the ether extract was neutralized by pouringgradually into a sodium carbonate solution. The entire neutralizedsolution was then transferred into a separatory funnel, and uponstanding, two layers separated, the top layer containing ether and salt;the lower layer, water and salt. The layers were separated and each wasevaporated to dryness. 33 grams of a white powder were obtained from theevaporated water layer. The evaporated ether layer was leached twicewith 54 A. P. I. naphtha, leaving 95 grams of white powder which wasnaphtha-insoluble. The characteristics of the thus separated products aswetting agents and detergent aids were determined by the method ofDraves and Clarkson as published in the Proc. Am. Assoc. Textile Chem.Colorists 1931, 109. The naphthainsoluble ether extract product had thefollowing wetting out characteristics:

Wetting numbers Weight cone. percent Neutral Second; 4

Accordingly, the naphtha-insoluble salt formed a clear neutral solutionwith water and showed a high wetting power. In hard water solutioncontaining 300 parts per million of calcium, the salt tended toprecipitate. In acidified solution, the salt caused some turbidity.

In some cases, it was found advantageous to carry out the condensationof the phosphorus oxy chloride with the alkylated phenol in the presenceof pyridine or an equivalent base. In most cases, however, the use ofthe base was found. unnecessary.

In a second experiment using the same type of procedure as explained inthe foregoing experiment, phenolic compounds from a petroleum oilfraction were reacted with P001: to form the di-ester chlorophosphate,and the resulting chlorophosphate was neutralized with potassiumhydroxide to obtain an ether-extracted naphthainsoluble salt having thefollowing wetting properties in a neutral aqueous solution:

Concentration of salt by weight in aqueous solutionpercent 0.2 0.1 0.07"

Wetting numbers in soft water sec 4.5 30 187 From these "data it can beobserved that the lower petroleum phenolic compounds, which comprisephenols containing parafflnic hydrocarbon side groups having a lowerhydrogen to carbon ratio than is present in simple alkyl groups, formsimple aryl ester salts of phosphoric .acid which are as effective inwetting power as s about C3.3H'1.5'C6H4OH. This deficiency of hydrogenin the saturated hydrocarbon substituent group is attributed to thepresence of cycloalkyl groups, which makes the hydroxyaromatic com-'pound partly simulate a naphthenic compound. The high'petroleum phenolshaving more than 10' carbon atoms per molecule show an even greaterdeficiency of hydrogen in this respect and also show the presence ofnon-phenolic oxygen. Though these higher petroleum phenols tend todarken readily in color, which may preclude their use in forming wettingagents for some purposes, they have marked resistance to alkalies andhigh organic solvent solubility which is a valuable property in manyrespects.

In a third experiment, a mol of phosphoric acid was esterified with onemol of tertiary amyl under some conditions may be made.

phenol to obtain a mono-ester, which,' in turn, was neutralized with twomole of sodium hydroxide to produce the corresponding di-sodium salt ofthe mono-ester, which was extracted by isopropyl alcohol. Theether-insoluble portion of the isopropyl alcohol extract made a clear 2%concentration solution with distilled water and showed a wetting numberof 37 seconds, and in a .2% concentration in hard water containing 300parts per million of calcium ion gave a perfectly clear solution havinga wetting number of 25 seconds. hols may be substituted for theisopropyl alcoholin the extraction.

Such experiments demonstrate that the naphtha-insoluble di-ester saltsof the phosphoric acid esters were particularly effective wetting agentsand detergent aids in neutral aqueous solutions, while theether-insoluble salts of the mono-esters were more effective in hardwater solutions. While certain classes of alkyl and cycloalkyl phenolshave been emphasized as being of major importance for selectionin'forming the improved wetting agents by esterification with,phosphoric acid or its halogen derivatives, various modifications toimprove performance For example, aliphatic alcohols, naphthenicalcohols, or aralkyl alcohols may be used auxiliary to the phenols informing the phosphoric acid esters.

, amino, sulfonate, sulfate, and halogen groups,

or other suspensoids in liqu1d vehicles, e. g.,

paints, water, inks, dye baths,- metal plating baths, sprayingcompositions, ore flotation mixtures, and lead treating baths. They maybe used to improve cosmetics, the wetting of glue, the mixing of cement,the finishing of pastes, the removal of grease from steel, the spreadingand a penetrating power of oils, the breaking of petroleum and wateremulsions of the type found in oil fields, the emulsification in lacquerforma- Other normally liquid aliphatic alco-- tion, the absorptionqualities of paper in paper manufacturing, etc.

This invention is not to be limited by the specific examples given norby any theory advanced on the mechanism of operation, but only by the 5appended claims in which it is intended to claim all novelty inherent inthe invention as broadly as the prior-art permits.

l. A base metal salt of a phosphoric acid ester 10 containing at leastone alkylaryl group and a total of 5 to 20 saturated carbon atoms in thealkyl radicals of said alkyl-aryl groups.

' 2. A mono basic alkali metal salt of a phosphoric acid ester in whichthe ester groups con-' sist in alkyl phenyl radicals containinganaverage total of 5 to about 20 alkylcarbon atoms per molecule-of thesalt.

3. A naphtha insoluble di-basic alkali metal salt of phosphoric acidpartially esterified by alkyl phenol molecules containing an averagetotal of 5 to 10 alkyl carbon atoms per molecule.

4. A di-basic alkali metal salt of a phosphoric acid ester in which theester group consists in an alkyl phenyl radical containing a total of 525 to about 20 alkyl carbon atoms per molecule of I the salt.

5. An ether-insoluble alkali metal salt of phosphoric acid partiallyesterified with an alkyl phenol containing 5 to 10 alkyl carbon atomsper 30 7 molecule.

6. The preparation of improved wetting agents by a process whichcomprises condensing with a pentavalent phosphorus compound whichhydrolyzes to phosphoric acid a limited quantity as of phenolicmolecules containing hydrocarbon substituents which have an averagetotal of 5 to 20 saturated carbon atoms per molecule of said ester saltsby a normally liquid alcohol and 5 leached with ether. 0

9. The preparation of improved wetting agents and detergent aids by aprocess which comprises condensing phosphoric acid with alkyl phenolshaving an average of 2.5 to 10 alkyl carbon atoms 55 per molecule andreacted in a quantity to produce phosphoric acid di-esters, thenneutralizing resulting acid esters with analkali metal base to obtaintheir ester salts.

10. The preparation of improved wetting 60 agents by a process whichcomprises condensing phosphorus oxychloride with a limited quantity 'ofphenolic compounds containing paraflinic bydrocarbon substituents havingan average of 2.5 to 10 carbon atoms per molecule to obtain phosphoricacid di-esters, and neutralizing said acid di-esters with an alkalimetal base to, obtain their ester salts.

11. The preparation of improved wetting agents by a process whichcomprises condensing phosphoric acid with an alkyl phenol containing 5to about 20- alkyl carbon atoms per molecule and reacted in a quantityto produce a phosphoric acid mono-ester, and neutralizing 5 in which Rrepresents at least one alkyl subthe resulting acid ester with an alkalimetal base to produce an ester salt.

DISCLA 2,219,050.L0uis A. Mikeska, Roselle, N. J.

which is 3.

LOUIS A. MIKESKA.

EMER

WETTING AGENT AND DETERGENT An).

Patent dated Oct. 22, 1940. Disclaimer filed Sept. 18, 1946, by theassignee,

Standard Oil Development Company. Hereby enters this disclaimer to claim1.

[Ofiicz'al Gazette October 22, 1.946.]

DISCLAIMER 2,219,050.-L0uis A. Mikeska, Roselle, N. J. WETTING AGENT ANDDETERGENT A11).

Patent dated Oct. 22,1940. Disclaimer filed Sept. 18, 1946, by theassignee, Standard Oil Development Company. Hereby enters thisdisclaimer to claim 1.

[Qfiicial Gazette October 22, 1946.]

